from math import sqrt
x1, y1, x2, y2 = (float(i) for i in input().split())
d = sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2)
print(d) from math import sqrt float(i) for i in input().split() for i in input().split() i input().split() ().split () input split for i in input().split() float(i) float i x1, y1, x2, y2 = (float(i) for i in input().split()) x1 (float(i) for i in input().split()) y1 x2 y2 d = sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2) d sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2) sqrt (x1 - x2) ** 2 + (y1 - y2) ** 2 (x1 - x2) ** 2 x1 - x2 x1 x2 2 (y1 - y2) ** 2 y1 - y2 y1 y2 2 print(d) print d x2, y2 = (float(i) for i in input().split()) (float(i) for i in input().split()) x2 x1, y1, x2, y2 = (float(i) for i in input().split()) (float(i) for i in input().split()) x1 d = sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2) sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2) d y1, x2, y2 = (float(i) for i in input().split()) (float(i) for i in input().split()) y1 y2 = (float(i) for i in input().split()) (float(i) for i in input().split()) y2
from math import sqrt
x1, y1, x2, y2 = (float(i) for i in input().split())
d = sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2)
print(d)